Photo Gallery: Marine Species Under Threat

Sea Otters

Photograph by Ming Wang, My Shot

A couple of charismatic sea otters, mother and child, share a meal of crab caught at Point Lobos State Reserve on California’s central coast. These animals do nearly everything in the water, including giving birth and sleeping. Fur hunters once pushed sea otters to the brink of extinction and a century ago only 1,000 to 2,000 individuals remained. Today the otters are protected, and their numbers have swelled to perhaps 150,000.

Bluefin Tuna

Photograph by Brian J. Skerry, National Geographic

Schooling bluefin tuna swim in an open-ocean pen off the Spanish coast, where they will be fattened up to satisfy human palates. Bluefins are some of the sea’s fastest fishes, reaching top speeds of some 43 miles (70 kilometers) an hour. But they’ve been unable to outrun fishing fleets, which have pushed some populations, like the Atlantic bluefin, toward the edge of extinction. Scientists warn that overharvesting continues unabated despite feeble international efforts at regulating the catch.

Dugong

Photograph by David Doubilet, National Geographic

A dugong forages in the seagrass meadows of Shark Bay, Western Australia. These marine mammals, like their manatee relatives, must surface every five minutes or so for a fresh breath. This behavior, and their typically slow movements, made them easy marks for hunters seeking dugong meat, oil, and teeth in coastal waters from East Africa to Australia. Dugongs are now protected, but their population status remains precarious.

Leatherback Turtle

Photograph by Brian J. Skerry, National Geographic

A leatherback turtle emerges from the surf in search of a nesting site on Trinidad’s Matura Beach. Leatherbacks are the world’s largest turtles, topping the scales at more than 2,000 pounds (900 kilograms). They are also among the oldest, part of a family with roots stretching back 100 million years. These turtles are found in all the world’s temperate or tropical seas—but not in the numbers they once were. Today leatherbacks are listed as endangered under the U.S. Endangered Species Act.

Sawfish

Photograph by Doug Perrine, SeaPics

A sawfish stretches its namesake snout across the floor of the Gulf of Mexico. This animal uses its toothy “saw” to sense buried crustaceans or bottom-dwelling fish, and to stun and kill them. Sawfish, which can reach lengths of 25 feet (7 meters), are related to sharks, skates, and rays. They haunt shallow waters like bays and estuaries worldwide—and some species even ascend freshwater rivers. It’s thought that sawfish populations have been reduced by some 90 percent due to habitat loss and accidental entanglements in fishing nets.

Humphead Wrasse

Large lips and a forehead hump are hallmarks of the reef-dwelling humphead wrasse, popular with divers and fishermen across much of the Indo-Pacific. Incredibly, some humphead wrasses are born as females but undergo sex changes around age nine and end their lives as males. These big (420-pound/190-kilogram) fish live long lives, more than 30 years, and probably never occurred in great densities.

Polar Bears

Photograph by Paul Nicklen, National Geographic

Churchill, Manitoba, Canada, is home sweet home to this polar bear and her two cubs. Polar bears typically have twins and teach their offspring to hunt and survive during the first 28 months of their lives. With thick layers of fat and fur, the bears are well prepared for cold climes. They prowl Arctic ice sheets and swim in frigid waters in search of seals and other prey. In 2008 the polar bear became the first animal to be added to the U.S. Endangered Species list because of climate change.

Whale Shark

Photograph by Colin Parker, My Shot

When it comes to feasting the whale shark is more whale than shark—this filter feeder simply opens its enormous mouth and swims to collect plankton and small fish. The ocean’s largest fish, whale sharks grow to lengths rivaling those of a typical school bus (40 feet/12 meters). The sharks are gentle giants, but their vulnerable populations are targeted by fisheries of Asian nations like Taiwan and the Philippines.

Manatees

Photograph by Barry Kulick, Your Shot

Two manatees enjoy the warm waters at the head of Florida’s spring-fed Homosassa River. During cold snaps the docile marine mammals congregate en masse at such spots—but extreme freezes like that of January 2010 can still cause dozens of deaths. Manatees are born underwater and never leave it—though they must surface to breathe every few minutes. Much of their downtime is spent grazing on grasses—an adult can eat a tenth of its own 1,300-pound (600-kilogram) weight in just 24 hours.

Polar Bear

Photograph by Paul Nicklen, National Geographic

A playful polar bear is clearly at home in the chilly clime of Churchill, Manitoba, Canada—but these kings of the Canadian tundra may have to move by mid-century. Climate change models suggest that sea ice loss in the Wapusk National Park region will be significant, depriving polar bears of the coastal platform from which they hunt for seals and other marine mammals.

Hawksbill Turtle

A hawksbill turtle glides just above the floor of a marine sanctuary near Saba, Netherlands Antilles. These sea turtles frequent tropical coastlines worldwide, within easy reach of nesting beaches and reefs rich with favored fare—a typical adult eats 1,200 pounds (544 kilograms) of sponges a year. Hawksbills are endangered because their beachfront nesting grounds and coral reef feeding grounds are shrinking. Humans also target the turtles for food and shell products.

Blue Whale

Photograph by Flip Nicklin, National Geographic

Even in the immensity of the Pacific the largest animal ever to live on Earth appears, well, extremely large. The blue whale packs on its nearly 200 tons of body mass by consuming enormous quantities of tiny krill—some four tons every day. After decades of being hunted, the whales finally received protection in 1966. But their populations have been slow to recover, and the blue whale is still endangered.

Engage, Conserve, Restore

The National Geographic Society’s freshwater initiative is a multi-year global effort to inspire and empower individuals and communities to conserve freshwater and preserve the extraordinary diversity of life that rivers, lakes, and wetlands sustain.